Hand Painting a Guitar Pedal

Today I’m going to show you how you can prepare and paint an aluminium surface using acrylic paints. Even if you’re not painting a guitar pedal, this video will be useful if you want to paint on aluminium that hasn't been specifically treated for painting.

Aluminium guitar pedal enclosure

Fine grit sandpaper

Citrus brush cleaner

Masking tape

Gesso

Acrylic paint

Brushes

Scalpel knife

Deco art clear pouring topcoat (optional: use a Crystal Clear spray varnish instead)

Because I’m new at pedal building, I decided to make things a little easier on myself by choosing a pre-drilled enclosure. If your enclosure needs to be drilled, you’ll want to do this before you start to paint.

The very first step is to sand the aluminium with some fine grit sandpaper, then to clean the surface to get rid of as much dirt and oil as you can. I wiped some citrus paint brush cleaner over the surface of my pedal, but you could use soapy water or any other suitable cleaner that you have available.

When you’ve cleaned the outside of the pedal, it’s a good idea to use some masking tape or washi tape on the inside of the pedal to cover the drilled out holes. This will help stop your paint and varnish from dripping inside the case.

When you’ve masked all the areas you need to, it’s time to prime the outside surface of the pedal. I’ve seen some people draw directly onto their pedals with paint pens, which can work ok, but you’ll get better paint adhesion if you prime the surface before you paint. I’ve also seen some people using specialised metal aerosol primer, which you can use if you want to, but I wanted to use what I already had, which was the standard type of gesso that you’d use to prime canvases and wood. I ended up painting about three coats of gesso onto the aluminium, letting each coat dry before applying the next one. If you want to, you can sand the gesso lightly between each coat to get a smoother surface.

Leave your gesso to dry fully overnight before painting.

I normally paint with oils, but those take months to dry, so I used acrylics for this project because they’re durable and dry quickly, which is important with a pedal enclosure as they're made to be stood on.

I recommend mixing your own colours as it's less expensive and opens up a wider variety of options, so you can see that I put some neutral red, yellow and blue primaries out on my palette, along with titanium white and Payne’s grey, which is a dark blue/grey colour that I used in place of black. I use a palette knife to mix everything I need from these colours, and occasionally use my brush to mix small amounts of colour.

To sketch out the basic shape of my painting, I used a coloured pencil. It’s better to use coloured pencils rather than greylead pencils for this, as the pigments in greylead pencils can bleed through the paint. If you choose a coloured pencil similar to the colours you’re painting with, it will blend in really well without bleeding through.

After sketching out my heron, I used some base colours to block in the main shapes.

I painted wet into wet for this image, mixing colours on my palette then blending them further on the image as I painted. I used a reference photo that I took a few years ago for this image, and I recommend doing that if you're not painting an abstract design.

I used three main brushes to paint my image. Large areas of colour and feather shading were painted with two flat square brushes. The two I used for this project were an Isabey size 14 Mangou brush and a smaller Raphael Kevrin brush in size 8; both are made from stiff but soft synthetic fibres designed to mimic mongoose hair.

For the fine detail line work and lettering I used a very small round brush; mine is a Raphael Kaerell round synthetic brush in size 0.

The best method and most efficient method I find for painting like this is to start with your larger brushes and move down in size as you add more and more detail. If you'd like to see my painting process in detail, be sure to watch the video.

If you want to paint stripes or sharp lines, use some low tack masking or washi tape to mask off areas then paint over the top and remove the tape carefully before the paint dries. Be sure to only apply the tape over other areas of paint when those areas are dry to the touch.

If you want to paint other shapes, such as circles, you can put a small coin or other item down and trace around it with a coloured pencil before filling the area in with paint.

Leave your painting in a warm, dry spot for at least three days before applying your varnish.

Acrylic paint feels dry to the touch within about half an hour, but it can take around three days for it to dry all the way through. If you varnish your painting before it’s completely dry, you run the risk of trapping moisture inside, which could cause problems in the long run.

I would normally use a spray varnish like crystal clear to varnish my pedal, but because we were still in pandemic lockdown when I made this, I chose to paint on a varnish with a brush, as getting aerosols delivered is really tricky and expensive.

I went with a heavy duty acrylic resin varnish that’s actually made for pouring and isn’t particularly suitable for using with a brush, but I just used a few coats and tried to apply it as carefully as I could. Whatever varnish you choose, apply a couple of coats, leaving it to dry in-between.

It can be useful to prop your enclosure up on something while you varnish it so that you can coat the sides easily without it touching your table and without you needing to touch the outside of the enclosure to move it around.

When the varnish is dry, you can remove the masking tape from the inside of your enclosure. If you need to tidy up around the holes, you can use a sharp scalpel to carefully cut away any extra paint and varnish. Your enclosure is now ready and waiting for its electronics!